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Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate

Includes abstract.

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Bibliographic Details
Main Author: Duku, Porogo
Other Authors: Petersen, Jochen
Format: Thesis
Language:English
Published: Centre for Bioprocess Engineering Research 2014
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access_status_str Open Access
author Duku, Porogo
author2 Petersen, Jochen
author_browse Duku, Porogo
Petersen, Jochen
author_facet Petersen, Jochen
Duku, Porogo
author_sort Duku, Porogo
collection Thesis
description Includes abstract.
format Thesis
id oai:open.uct.ac.za:11427/5380
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:48:40.482Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Centre for Bioprocess Engineering Research
publisherStr Centre for Bioprocess Engineering Research
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/5380 Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate Duku, Porogo Petersen, Jochen Minnaar, Sanet Harrison, STL Bioprocess Engineering Includes abstract. Includes bibliographical references. Bioleaching can be categorized as being either stirred tank type (i.e. bio-oxidation) or irrigation type (i.e. heap/dump bioleaching) yet studies investigating the kinetics of bioleaching systems mostly use empirical data determined from stirred tank type and initial rate experiments in batch cultures or using iso-potential devices. Rate equations deduced from such empirical data is then used to model both the stirred tank type and irrigation type bioleaching systems overlooking the possibility that there may be significant differences in their environments and therefore the kinetics. Tank bioleaching systems are well mixed suspension systems dominated by planktonic microorganisms (freely suspended in the liquid medium). Heap bioleaching systems on the contrary, are heterogeneous in nature with chemical and physical conditions changing over time and are dominated by sessile microorganisms (attached microorganisms to the surface of a solid). The heap bioleaching system is therefore highly complex compared to the stirred tank-type systems. Microbial growth in bioleaching systems significantly influence the overall bioleaching kinetics yet biological kinetic effects in sessile/ attached environments are not well understood. Heap and dump leaching account for about 20% of the world’s copper production and are becoming popular methods of copper production from leaching low grade ores. It is therefore important that the kinetics of irrigation type bioleaching systems are well understood. A strategy to determine the microbial kinetics of a sessile microbial population is enforced in this study. From this, empirical data determined from irrigation type environments can then be used to derive equations which can be used to accurately model heap bioleaching systems. Three sets of experiments were conducted to try and achieve this: i. planktonic experiments - investigating the microbial kinetics of a planktonic microbial population ii. attachment experiments - investigating the nature of growth of the microbial population to the surface of a solid substrate during attachment to create a sessile microbial population iii. sessile experiments - investigating the microbial kinetics of the sessile microbial population A pure culture of Leptospirillum ferriphilum (a mesophilic, ferrous iron oxidizing bioleachingmicroorganism) was used in this study. Planktonic experiments were conducted in a completely mixed, well aerated continuous stirred tank reactor (CSTR) with a 1 litre working volume, operating at a pH of about 1.3 and temperature of 37oC. Attachment and sessile experiments were conducted using a CSTR with similar conditions to the planktonic experimental, however the system was modified by introducing a packed bed vessel (PBR) attached as a closed loop to the CSTR. Solution drawn from the CSTR was then continuously pumped through the PBR and back to the CSTR. 2014-07-31T11:13:33Z 2014-07-31T11:13:33Z 2011 Master Thesis Masters MSc http://hdl.handle.net/11427/5380 eng application/pdf Centre for Bioprocess Engineering Research Faculty of Engineering and the Built Environment University of Cape Town
spellingShingle Bioprocess Engineering
Duku, Porogo
Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate
thesis_degree_str Master's
title Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate
title_full Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate
title_fullStr Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate
title_full_unstemmed Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate
title_short Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate
title_sort biooxidation kinetics of leptospirillum ferriphilum attached to a defined solid substrate
topic Bioprocess Engineering
url http://hdl.handle.net/11427/5380
work_keys_str_mv AT dukuporogo biooxidationkineticsofleptospirillumferriphilumattachedtoadefinedsolidsubstrate